Eman Shaheen - Academia.edu (original) (raw)

Papers by Eman Shaheen

Journal of Oral and Maxillofacial Surgery, 2017

The aim of this study was to systematically review methods used for assessing the accuracy of 3-d... more The aim of this study was to systematically review methods used for assessing the accuracy of 3-dimensional virtually planned orthognathic surgery in an attempt to reach an objective assessment protocol that could be universally used. Materials and Methods: A systematic review of the currently available literature, published until September 12, 2016, was conducted using PubMed as the primary search engine. We performed secondary searches using the Cochrane Database, clinical trial registries, Google Scholar, and Embase, as well as a bibliography search. Included articles were required to have stated clearly that 3-dimensional virtual planning was used and accuracy assessment performed, along with validation of the planning and/or assessment method. Descriptive statistics and quality assessment of included articles were performed. Results: The initial search yielded 1,461 studies. Only 7 studies were included in our review. An important variability was found regarding methods used for 1) accuracy assessment of virtually planned orthognathic surgery or 2) validation of the tools used. Included studies were of moderate quality; reviewers' agreement regarding quality was calculated to be 0.5 using the Cohen k test. Conclusions: On the basis of the findings of this review, it is evident that the literature lacks consensus regarding accuracy assessment. Hence, a protocol is suggested for accuracy assessment of virtually planned orthognathic surgery with the lowest margin of error.

Genes, 2021

Type 2 diabetes mellitus (T2DM) and hypertension are common chronic diseases mainly associated wi... more Type 2 diabetes mellitus (T2DM) and hypertension are common chronic diseases mainly associated with the development and progression of end-stage renal disease (ESRD) leading to morbidity and mortality. Gene polymorphisms linked to the renin–angiotensin (AGT)–aldosterone system (RAAS) were broadly inspected in patients with diabetic nephropathy (DN) and hypertension. This study aimed to investigate the association of AGT gene polymorphisms (rs699 and rs4762) with ESRD in T2DM hypertensive Egyptian patients. Genotyping of rs699 and rs4762 was conducted using the tetra-primers amplification refractory mutation system (ARMS-PCR). The allelic distribution analysis was performed on 103 healthy control subjects, 97 non-ESRD patients, and 104 patients with ESRD. The allelic frequencies of AGT gene polymorphisms (rs4762 and rs699) in all study participants were assessed. For the non-ESRD group, the frequencies of the alleles of AGT-rs4762 (χ2 = 31.88, p < 0.001, OR = 5.17, CI 95%: 2.81–9....

Journal of Stomatology, Oral and Maxillofacial Surgery

Journal of Oral and Maxillofacial Surgery, 2021

Purpose: Contemporary literature suggests a similar transverse stability of a surgical-assisted r... more Purpose: Contemporary literature suggests a similar transverse stability of a surgical-assisted rapid palatal expansion and a segmented Le Fort I osteotomy. The aim of this study was to compare postoperative complications of 1-stage (segmental maxillary osteotomy) and 2-stage (surgical-assisted rapid palatal expansion followed by Le Fort I osteotomy) treated patients to determine the preferred treatment strategy. Materials and Methods: This retrospective study included 74 consecutive patients (age range: 14-57 years; 36 males, 38 females) with a moderate transverse maxillary hypoplasia: 32 patients were treated in a 1-stage protocol and 42 in a 2-stage protocol with a postoperative follow-up of at least 1 year. Dental complications such as loss of teeth, gingival dehiscence, periodontal bone loss, apical root resorption, and surgical complications such as pain, hemorrhage, altered neurosensitivity, wound infection, aseptic necrosis were analyzed. Univariate analysis consisted of a generalized linear model with logit link or Fisher exact test. Results: No significant difference was found for group characteristics except for longer orthodontic treatment time in the 2-stage group. Incidence and severity of complications were comparable for the 1-stage and 2-stage patients. Only overall pain was significantly greater in the 2-stage patient group (P = .038). Conclusions: Considering a similar complication rate and transversal stability, the choice between 1stage and 2-stage approach for patients with a moderate transverse maxillary hypoplasia should be patient specific.

Poster: "ECR 2010 / C-0324 / Towards a method for simulating lesions into digital breast tom... more Poster: "ECR 2010 / C-0324 / Towards a method for simulating lesions into digital breast tomosynthesis images" by: "E. Shaheen, A. Van Steen, L. Cockmartin, N. Marshall, F. Zanca, C. Van Ongeval, G. Zhang, H. Bosmans; Leuven/BE"

Background: Upper gastrointestinal bleeding is a potentially life-threatening abdominal emergency... more Background: Upper gastrointestinal bleeding is a potentially life-threatening abdominal emergency that remains a common cause of hospitalization. The role of the nurse in managing a patient with upper GI bleeding requires specific attention. Aim: Evaluate effect of implementing training program regarding care of patients with upper GIT bleeding on nurses' knowledge. Subjects & Method: Design: A Quasi experimental (pre/post –test) research design was used: Setting: study was conducted at Hematemesis Unit of Emergency Hospital located in Critical Situations and Convalescence Hospital affiliated to Mansoura University Hospitals. Subjects: Convenient samples of 25 male and female nurses who are dealing with upper gastrointestinal bleeding patients are selected from Hematemesis Unit of Emergency Hospital, Mansoura University, Egypt. Tools: Two tools were used to collect data; demographic characteristics of the nurses and nurses’ knowledge assessment self-administrated questionnaire ....

The Journal of forensic odonto-stomatology, 2017

BACKGROUND Previous research proposed the use of the mandibular midline neurovascular canal struc... more BACKGROUND Previous research proposed the use of the mandibular midline neurovascular canal structures as a forensic finger print. In their observer study, an average correct identification of 95% was reached which triggered this study. AIM To present a semi-automatic computer recognition approach to replace the observers and to validate the accuracy of this newly proposed method. MATERIALS AND METHODS Imaging data from Computer Tomography (CT) and Cone Beam Computer Tomography (CBCT) of mandibles scanned at two different moments were collected to simulate an AM and PM situation where the first scan presented AM and the second scan was used to simulate PM. Ten cases with 20 scans were used to build a classifier which relies on voxel based matching and results with classification into one of two groups: "Unmatched" and "Matched". This protocol was then tested using five other scans out of the database. Unpaired t-testing was applied and accuracy of the computerize...

Journal of Dentistry, 2021

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

PLOS ONE, 2020

The use of high quality facemasks is indispensable in the light of the current COVID pandemic. Th... more The use of high quality facemasks is indispensable in the light of the current COVID pandemic. This study proposes a fully automatic technique to design a face specific mask. Through the use of stereophotogrammetry, computer-assisted design and three-dimensional (3D) printing, we describe a protocol for manufacturing facemasks perfectly adapted to the individual face characteristics. The face specific mask was compared to a universal design of facemask and different filter container’s designs were merged with the mask body. Subjective assessment of the face specific mask demonstrated tight closure at the nose, mouth and chin area, and permits the normal wearing of glasses. A screw-drive locking system is advised for easy assembly of the filter components. Automation of the process enables high volume production but still allows sufficient designer interaction to answer specific requirements. The suggested protocol can be used to provide more comfortable, effective and sustainable so...

Journal of Dentistry, 2021

Automatic tooth segmentation and classification from cone beam computed tomography (CBCT) have be... more Automatic tooth segmentation and classification from cone beam computed tomography (CBCT) have become an integral component of the digital dental workflows. Therefore, the aim of this study was to develop and validate a deep learning approach for an automatic tooth segmentation and classification from CBCT images. Methods: A dataset of 186 CBCT scans was acquired from two CBCT machines with different acquisition settings. An artificial intelligence (AI) framework was built to segment and classify teeth. Teeth were segmented in a three-step approach with each step consisting of a 3D U-Net and step 2 included classification. The dataset was divided into training set (140 scans) to train the model based on ground-truth segmented teeth, validation set (35 scans) to test the model performance and test set (11 scans) to evaluate the model performance compared to ground-truth. Different evaluation metrics were used such as precision, recall rate and time. Results: The AI framework correctly segmented teeth with optimal precision (0.98±0.02) and recall (0.83±0.05). The difference between the AI model and ground-truth was 0.56±0.38 mm based on 95% Hausdorff distance confirming the high performance of AI compared to ground-truth. Furthermore, segmentation of all the teeth within a scan was more than 1800 times faster for AI compared to that of an expert. Teeth classification also performed optimally with a recall rate of 98.5% and precision of 97.9%. Conclusions: The proposed 3D U-Net based AI framework is an accurate and time-efficient deep learning system for automatic tooth segmentation and classification without expert refinement. Clinical significance: The proposed system might enable potential future applications for diagnostics and treatment planning in the field of digital dentistry, while reducing clinical workload.

Journal of Dentistry, 2021

OBJECTIVES The present review systematically analyzed the accuracy of three-dimensional (3D) maxi... more OBJECTIVES The present review systematically analyzed the accuracy of three-dimensional (3D) maxillofacial skeletal models generated from desktop and professional 3D printers. DATA/SOURCES Electronic literature search was conducted in the following databases: PubMed, Embase, Web of Science and Cochrane Library up to September 2020. Two reviewers independently performed the study selection, data extraction and quality assessment of the included studies. Risk of bias was assessed using the Joanna Briggs Critical Appraisal Checklist for Diagnostic Test Accuracy. STUDY SELECTION/RESULTS The search strategy retrieved 5,680 articles. Following removal of duplicates, title and abstract screening and full-text reading, 20 publications were eligible to be included in the review which focused towards the accuracy of skeletal models generated from either desktop or professional printer. Both types of printers were defined based on their cost, size and layer thickness, where desktop printers cost between 1500−1500-1500−7000, build size of 10×10×10 inches or less and a minimum layer thickness of 100 microns. Whereas, the professional printer's cost was between 20,000−20,000- 20,000−200,000 with a build size of 12×12×12 inches or more and a layer thickness of as less as 3 microns. The risk of bias was found to be low to moderate. Meta-analysis results indicated no significant absolute mean difference (AMD) (p=0.9487) between desktop (0.12mm, 95% CI: 0.00-0.27mm) and professional printers (0.10mm, 95% CI: 0.04-0.16mm). Amongst the printing technology, material jetting (0.09mm, 95% CI: 0.00-0.17mm) and selective laser sintering (0.09mm, 95% CI: 0.00-0.26mm) offered the lowest AMD and the highest difference was observed with the fused deposition modeling (0.22mm, 95% CI: 0.00-0.53mm). CONCLUSIONS The maxillofacial skeletal models generated from desktop printers offered comparable accuracy to that acquired with professional printers. CLINICAL SIGNIFICANCE The desktop 3D printers may be a viable option to print maxillofacial skeletal models for surgical planning, simulation, guide manufacturing and education purposes.

Clinical and Experimental Dental Research, 2021

Objective: The aim of this study was to propose and validate a three-dimensional (3D) methodology... more Objective: The aim of this study was to propose and validate a three-dimensional (3D) methodology for the assessment of canine eruption in patients born with unilateral cleft lip and palate (UCLP) following secondary alveolar bone graft (SABG). Methods and Materials: A total of 10 patients (four females, six males; mean age: 8.8 years) with UCLP who underwent SABG were recruited. Pre-and 6-month postoperative cone-beam computed tomography (CBCT) was acquired for all patients. Postoperative data was registered onto pre-operative data utilizing voxel-based registration. Following superimposition, a segmentation process was applied to segment maxillary canine on both cleft and non-cleft side. Thereafter, translational and rotational changes in canine position were assessed for both cleft and non-cleft side by two observers. Results: The intra-class correlation coefficient (ICC) indicated excellent reliability (≥0.90) with inter and intra-observer error of less than 0.05 mm. The overall ICC was found to be high for assessing both translational and rotational changes. The mean absolute inter-and intra-observer difference for translational and rotational changes was found to be less than 1 mm and 3. Conclusion: The present method was found to be reliable proving to be clinically applicable for assessing maxillary canine eruption changes in both cleft and noncleft bone.

Acta Ophthalmologica, 2020

Fitting a customized ocular prosthesis for anophthalmic patients entails an artisanal labour‐exha... more Fitting a customized ocular prosthesis for anophthalmic patients entails an artisanal labour‐exhausting process and is standardly based on impression moulding of the socket, which may be anatomically inaccurate. The objective of the study was to design an impression‐free socket mould with three‐dimensional (3D) technology.

Imaging Science in Dentistry, 2020

Purpose: This study was conducted to objectively and subjectively compare the accuracy and reliab... more Purpose: This study was conducted to objectively and subjectively compare the accuracy and reliability of 2-dimensional (2D) photography and 3-dimensional (3D) soft tissue imaging. Materials and Methods: Facial images of 50 volunteers (25 males, 25 females) were captured with a Nikon D800 2D camera (Nikon Corporation, Tokyo, Japan), 3D stereophotogrammetry (SPG), and laser scanning (LS). All subjects were imaged in a relaxed, closed-mouth position with a normal smile. The 2D images were then exported to Mirror ® Software (Canfield Scientific, Inc, NJ, USA) and the 3D images into Proplan CMF ® software (version 2.1, Materialise HQ, Leuven, Belgium) for further evaluation. For an objective evaluation, 2 observers identified soft tissue landmarks and performed linear measurements on subjects' faces (direct measurements) and both linear and angular measurements on all images (indirect measurements). For a qualitative analysis, 10 dental observers and an expert in facial imaging (subjective gold standard) completed a questionnaire regarding facial characteristics. The reliability of the quantitative data was evaluated using intraclass correlation coefficients, whereas the Fleiss kappa was calculated for qualitative data. Results: Linear and angular measurements carried out on 2D and 3D images showed excellent inter-observer and intra-observer reliability. The 2D photographs displayed the highest combined total error for linear measurements. SPG performed better than LS, with borderline significance (P = 0.052). The qualitative assessment showed no significant differences among the 2D and 3D imaging modalities. Conclusion: SPG was found to a reliable and accurate tool for the morphological evaluation of soft tissue in comparison to 2D imaging and laser scanning.

The Open Dentistry Journal, 2018

Objectives: To assess the effect of two of the most commonly used sterilization techniques on 3D ... more Objectives: To assess the effect of two of the most commonly used sterilization techniques on 3D printed clinical objects. Materials & Methods: The two sterilization methods used in our hospital and investigated in this paper are: Steam heat and Gas plasma. Three objects were printed and tested in this study: a tooth replica, an orthognathic final splint, a surgical cutting guide for the purpose of mandible reconstruction. For each of the 3 objects, 4 copies were made: one original STL object, one copy of the object pre-sterilization, one copy of post-steam heat sterilization, and one copy of post-gas plasma sterilization. Each printed object was scanned using a high resolution CBCT protocol and the compared (morphologically and volumetrically). Results: At the level of volumetric changes, no difference was found between pre and post-sterilization for both methods evaluated. As for the morphological changes, only differences were noticed with the orthognathic splint object indicatin...

Biochemia medica, Jan 15, 2018

Analytical quality is an essential requirement for best practice in any medical laboratory. Lack ... more Analytical quality is an essential requirement for best practice in any medical laboratory. Lack of a harmonized approach for sigma calculation is considered an obstacle in the objective comparability of analytical performance among laboratories adopting sigma metrics. It is urgently needed that all laboratory professionals interested in the analytical quality to work hard towards harmonization protocol for sigma calculation in order to properly select their analytical goals. This study aims at harmonization of Sigma metrics calculation in four accredited Egyptian laboratories. This observational cross sectional study compared the sigma levels for certain biochemical parameters in the four participating laboratories. Coefficient of variation (CV) and bias were determined for some biochemical analytes, data assayed by different automated analysers in the four different accredited laboratories. The sigma level for the four medical laboratories was calculated for each biomedical parame...

STOMATOLOGY EDU JOURNAL, 2016

Introduction: Facial asymmetry is a three-dimensional problem and is common in humans. Depending ... more Introduction: Facial asymmetry is a three-dimensional problem and is common in humans. Depending on the severity of the condition and the cause, several treatment modalities are proposed. In this study, we report on our workflow treating facial mandibular asymmetries without malocclusion. Methodology: CT scans were used for preoperative planning and postoperative evaluation. 3D planning using the mirroring technique was presented and afterwards a simulated extension was 3D printed and used during the surgery for accurate harvesting and placement of the bone graft. Results: The surgical actual outcome when compared to the simulation revealed good approximation with a mean of 0.29 (± 1.73) mm. Conclusion: The proposed method can be considered promising for the treatment of facial mandibular asymmetry without affecting the occlusion. However, a larger scale prospective study should be conducted to confirm these findings.

Journal of Oral and Maxillofacial Surgery, 2017

Squamous odontogenic tumor is a rare benign epithelial odontogenic tumor of the jaw. Most are sol... more Squamous odontogenic tumor is a rare benign epithelial odontogenic tumor of the jaw. Most are solitary lesions, although rare multifocal lesions have been described. Maxillary lesions have more aggressive behavior. Because of their benign character, these lesions are usually treated using a conservative surgical approach with curettage and surgical enucleation. Here we present a case of a 29-year-old woman with multifocal lesions who was initially treated with conservative surgical therapy. Early recurrence 6-months post-surgery prompted more aggressive resection. The case is discussed in the context of current evidence related to the epidemiology, etiology, diagnosis, and therapy of squamous odontogenic tumors.

Journal of cranio-maxillo-facial surgery : official publication of the European Association for Cranio-Maxillo-Facial Surgery, 2017

To quantify the postoperative condylar remodelling and its role in skeletal relapse after bimaxil... more To quantify the postoperative condylar remodelling and its role in skeletal relapse after bimaxillary surgery. 50 patients with mandibular hypoplasia who underwent bimaxillary surgery were analyzed. CBCT scans were acquired preoperatively, one week postoperatively and two years postoperatively. 3D cephalometric analysis was carried out for each CBCT scan, after which the condylar volume analysis was performed. The maxilla was advanced by a mean of 2.1 mm with a corresponding mean relapse of 0.3 mm. The maxilla was impacted in 23 and extruded in 27 patients. The mean mandibular advancement was 7.8 mm. Two years after surgery a mean mandibular skeletal relapse of 1.3 mm was observed. 78% of condyles exhibited a postoperative reduction in volume of 179 mm(3) (mean), equivalent to 12.5 volume%. Postoperative condylar volume loss was correlated with mandibular skeletal relapse (r = 0.42, p < 0.01), but not with maxilla relapse. Linear regression analysis identified age, gender, amount...

Lecture Notes in Computer Science, 2010

Abstract. Observer performance experiments for lesion detection are an ac-cepted means of assessi... more Abstract. Observer performance experiments for lesion detection are an ac-cepted means of assessing the imaging performance of radiological imaging sys-tems. Simulation methods for clusters of microcalcifications have been proposed for creating images with abnormal ...

Journal of Oral and Maxillofacial Surgery, 2017

The aim of this study was to systematically review methods used for assessing the accuracy of 3-d... more The aim of this study was to systematically review methods used for assessing the accuracy of 3-dimensional virtually planned orthognathic surgery in an attempt to reach an objective assessment protocol that could be universally used. Materials and Methods: A systematic review of the currently available literature, published until September 12, 2016, was conducted using PubMed as the primary search engine. We performed secondary searches using the Cochrane Database, clinical trial registries, Google Scholar, and Embase, as well as a bibliography search. Included articles were required to have stated clearly that 3-dimensional virtual planning was used and accuracy assessment performed, along with validation of the planning and/or assessment method. Descriptive statistics and quality assessment of included articles were performed. Results: The initial search yielded 1,461 studies. Only 7 studies were included in our review. An important variability was found regarding methods used for 1) accuracy assessment of virtually planned orthognathic surgery or 2) validation of the tools used. Included studies were of moderate quality; reviewers' agreement regarding quality was calculated to be 0.5 using the Cohen k test. Conclusions: On the basis of the findings of this review, it is evident that the literature lacks consensus regarding accuracy assessment. Hence, a protocol is suggested for accuracy assessment of virtually planned orthognathic surgery with the lowest margin of error.

Genes, 2021

Type 2 diabetes mellitus (T2DM) and hypertension are common chronic diseases mainly associated wi... more Type 2 diabetes mellitus (T2DM) and hypertension are common chronic diseases mainly associated with the development and progression of end-stage renal disease (ESRD) leading to morbidity and mortality. Gene polymorphisms linked to the renin–angiotensin (AGT)–aldosterone system (RAAS) were broadly inspected in patients with diabetic nephropathy (DN) and hypertension. This study aimed to investigate the association of AGT gene polymorphisms (rs699 and rs4762) with ESRD in T2DM hypertensive Egyptian patients. Genotyping of rs699 and rs4762 was conducted using the tetra-primers amplification refractory mutation system (ARMS-PCR). The allelic distribution analysis was performed on 103 healthy control subjects, 97 non-ESRD patients, and 104 patients with ESRD. The allelic frequencies of AGT gene polymorphisms (rs4762 and rs699) in all study participants were assessed. For the non-ESRD group, the frequencies of the alleles of AGT-rs4762 (χ2 = 31.88, p < 0.001, OR = 5.17, CI 95%: 2.81–9....

Journal of Stomatology, Oral and Maxillofacial Surgery

Journal of Oral and Maxillofacial Surgery, 2021

Purpose: Contemporary literature suggests a similar transverse stability of a surgical-assisted r... more Purpose: Contemporary literature suggests a similar transverse stability of a surgical-assisted rapid palatal expansion and a segmented Le Fort I osteotomy. The aim of this study was to compare postoperative complications of 1-stage (segmental maxillary osteotomy) and 2-stage (surgical-assisted rapid palatal expansion followed by Le Fort I osteotomy) treated patients to determine the preferred treatment strategy. Materials and Methods: This retrospective study included 74 consecutive patients (age range: 14-57 years; 36 males, 38 females) with a moderate transverse maxillary hypoplasia: 32 patients were treated in a 1-stage protocol and 42 in a 2-stage protocol with a postoperative follow-up of at least 1 year. Dental complications such as loss of teeth, gingival dehiscence, periodontal bone loss, apical root resorption, and surgical complications such as pain, hemorrhage, altered neurosensitivity, wound infection, aseptic necrosis were analyzed. Univariate analysis consisted of a generalized linear model with logit link or Fisher exact test. Results: No significant difference was found for group characteristics except for longer orthodontic treatment time in the 2-stage group. Incidence and severity of complications were comparable for the 1-stage and 2-stage patients. Only overall pain was significantly greater in the 2-stage patient group (P = .038). Conclusions: Considering a similar complication rate and transversal stability, the choice between 1stage and 2-stage approach for patients with a moderate transverse maxillary hypoplasia should be patient specific.

Poster: "ECR 2010 / C-0324 / Towards a method for simulating lesions into digital breast tom... more Poster: "ECR 2010 / C-0324 / Towards a method for simulating lesions into digital breast tomosynthesis images" by: "E. Shaheen, A. Van Steen, L. Cockmartin, N. Marshall, F. Zanca, C. Van Ongeval, G. Zhang, H. Bosmans; Leuven/BE"

Background: Upper gastrointestinal bleeding is a potentially life-threatening abdominal emergency... more Background: Upper gastrointestinal bleeding is a potentially life-threatening abdominal emergency that remains a common cause of hospitalization. The role of the nurse in managing a patient with upper GI bleeding requires specific attention. Aim: Evaluate effect of implementing training program regarding care of patients with upper GIT bleeding on nurses' knowledge. Subjects & Method: Design: A Quasi experimental (pre/post –test) research design was used: Setting: study was conducted at Hematemesis Unit of Emergency Hospital located in Critical Situations and Convalescence Hospital affiliated to Mansoura University Hospitals. Subjects: Convenient samples of 25 male and female nurses who are dealing with upper gastrointestinal bleeding patients are selected from Hematemesis Unit of Emergency Hospital, Mansoura University, Egypt. Tools: Two tools were used to collect data; demographic characteristics of the nurses and nurses’ knowledge assessment self-administrated questionnaire ....

The Journal of forensic odonto-stomatology, 2017

BACKGROUND Previous research proposed the use of the mandibular midline neurovascular canal struc... more BACKGROUND Previous research proposed the use of the mandibular midline neurovascular canal structures as a forensic finger print. In their observer study, an average correct identification of 95% was reached which triggered this study. AIM To present a semi-automatic computer recognition approach to replace the observers and to validate the accuracy of this newly proposed method. MATERIALS AND METHODS Imaging data from Computer Tomography (CT) and Cone Beam Computer Tomography (CBCT) of mandibles scanned at two different moments were collected to simulate an AM and PM situation where the first scan presented AM and the second scan was used to simulate PM. Ten cases with 20 scans were used to build a classifier which relies on voxel based matching and results with classification into one of two groups: "Unmatched" and "Matched". This protocol was then tested using five other scans out of the database. Unpaired t-testing was applied and accuracy of the computerize...

Journal of Dentistry, 2021

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

PLOS ONE, 2020

The use of high quality facemasks is indispensable in the light of the current COVID pandemic. Th... more The use of high quality facemasks is indispensable in the light of the current COVID pandemic. This study proposes a fully automatic technique to design a face specific mask. Through the use of stereophotogrammetry, computer-assisted design and three-dimensional (3D) printing, we describe a protocol for manufacturing facemasks perfectly adapted to the individual face characteristics. The face specific mask was compared to a universal design of facemask and different filter container’s designs were merged with the mask body. Subjective assessment of the face specific mask demonstrated tight closure at the nose, mouth and chin area, and permits the normal wearing of glasses. A screw-drive locking system is advised for easy assembly of the filter components. Automation of the process enables high volume production but still allows sufficient designer interaction to answer specific requirements. The suggested protocol can be used to provide more comfortable, effective and sustainable so...

Journal of Dentistry, 2021

Automatic tooth segmentation and classification from cone beam computed tomography (CBCT) have be... more Automatic tooth segmentation and classification from cone beam computed tomography (CBCT) have become an integral component of the digital dental workflows. Therefore, the aim of this study was to develop and validate a deep learning approach for an automatic tooth segmentation and classification from CBCT images. Methods: A dataset of 186 CBCT scans was acquired from two CBCT machines with different acquisition settings. An artificial intelligence (AI) framework was built to segment and classify teeth. Teeth were segmented in a three-step approach with each step consisting of a 3D U-Net and step 2 included classification. The dataset was divided into training set (140 scans) to train the model based on ground-truth segmented teeth, validation set (35 scans) to test the model performance and test set (11 scans) to evaluate the model performance compared to ground-truth. Different evaluation metrics were used such as precision, recall rate and time. Results: The AI framework correctly segmented teeth with optimal precision (0.98±0.02) and recall (0.83±0.05). The difference between the AI model and ground-truth was 0.56±0.38 mm based on 95% Hausdorff distance confirming the high performance of AI compared to ground-truth. Furthermore, segmentation of all the teeth within a scan was more than 1800 times faster for AI compared to that of an expert. Teeth classification also performed optimally with a recall rate of 98.5% and precision of 97.9%. Conclusions: The proposed 3D U-Net based AI framework is an accurate and time-efficient deep learning system for automatic tooth segmentation and classification without expert refinement. Clinical significance: The proposed system might enable potential future applications for diagnostics and treatment planning in the field of digital dentistry, while reducing clinical workload.

Journal of Dentistry, 2021

OBJECTIVES The present review systematically analyzed the accuracy of three-dimensional (3D) maxi... more OBJECTIVES The present review systematically analyzed the accuracy of three-dimensional (3D) maxillofacial skeletal models generated from desktop and professional 3D printers. DATA/SOURCES Electronic literature search was conducted in the following databases: PubMed, Embase, Web of Science and Cochrane Library up to September 2020. Two reviewers independently performed the study selection, data extraction and quality assessment of the included studies. Risk of bias was assessed using the Joanna Briggs Critical Appraisal Checklist for Diagnostic Test Accuracy. STUDY SELECTION/RESULTS The search strategy retrieved 5,680 articles. Following removal of duplicates, title and abstract screening and full-text reading, 20 publications were eligible to be included in the review which focused towards the accuracy of skeletal models generated from either desktop or professional printer. Both types of printers were defined based on their cost, size and layer thickness, where desktop printers cost between 1500−1500-1500−7000, build size of 10×10×10 inches or less and a minimum layer thickness of 100 microns. Whereas, the professional printer's cost was between 20,000−20,000- 20,000−200,000 with a build size of 12×12×12 inches or more and a layer thickness of as less as 3 microns. The risk of bias was found to be low to moderate. Meta-analysis results indicated no significant absolute mean difference (AMD) (p=0.9487) between desktop (0.12mm, 95% CI: 0.00-0.27mm) and professional printers (0.10mm, 95% CI: 0.04-0.16mm). Amongst the printing technology, material jetting (0.09mm, 95% CI: 0.00-0.17mm) and selective laser sintering (0.09mm, 95% CI: 0.00-0.26mm) offered the lowest AMD and the highest difference was observed with the fused deposition modeling (0.22mm, 95% CI: 0.00-0.53mm). CONCLUSIONS The maxillofacial skeletal models generated from desktop printers offered comparable accuracy to that acquired with professional printers. CLINICAL SIGNIFICANCE The desktop 3D printers may be a viable option to print maxillofacial skeletal models for surgical planning, simulation, guide manufacturing and education purposes.

Clinical and Experimental Dental Research, 2021

Objective: The aim of this study was to propose and validate a three-dimensional (3D) methodology... more Objective: The aim of this study was to propose and validate a three-dimensional (3D) methodology for the assessment of canine eruption in patients born with unilateral cleft lip and palate (UCLP) following secondary alveolar bone graft (SABG). Methods and Materials: A total of 10 patients (four females, six males; mean age: 8.8 years) with UCLP who underwent SABG were recruited. Pre-and 6-month postoperative cone-beam computed tomography (CBCT) was acquired for all patients. Postoperative data was registered onto pre-operative data utilizing voxel-based registration. Following superimposition, a segmentation process was applied to segment maxillary canine on both cleft and non-cleft side. Thereafter, translational and rotational changes in canine position were assessed for both cleft and non-cleft side by two observers. Results: The intra-class correlation coefficient (ICC) indicated excellent reliability (≥0.90) with inter and intra-observer error of less than 0.05 mm. The overall ICC was found to be high for assessing both translational and rotational changes. The mean absolute inter-and intra-observer difference for translational and rotational changes was found to be less than 1 mm and 3. Conclusion: The present method was found to be reliable proving to be clinically applicable for assessing maxillary canine eruption changes in both cleft and noncleft bone.

Acta Ophthalmologica, 2020

Fitting a customized ocular prosthesis for anophthalmic patients entails an artisanal labour‐exha... more Fitting a customized ocular prosthesis for anophthalmic patients entails an artisanal labour‐exhausting process and is standardly based on impression moulding of the socket, which may be anatomically inaccurate. The objective of the study was to design an impression‐free socket mould with three‐dimensional (3D) technology.

Imaging Science in Dentistry, 2020

Purpose: This study was conducted to objectively and subjectively compare the accuracy and reliab... more Purpose: This study was conducted to objectively and subjectively compare the accuracy and reliability of 2-dimensional (2D) photography and 3-dimensional (3D) soft tissue imaging. Materials and Methods: Facial images of 50 volunteers (25 males, 25 females) were captured with a Nikon D800 2D camera (Nikon Corporation, Tokyo, Japan), 3D stereophotogrammetry (SPG), and laser scanning (LS). All subjects were imaged in a relaxed, closed-mouth position with a normal smile. The 2D images were then exported to Mirror ® Software (Canfield Scientific, Inc, NJ, USA) and the 3D images into Proplan CMF ® software (version 2.1, Materialise HQ, Leuven, Belgium) for further evaluation. For an objective evaluation, 2 observers identified soft tissue landmarks and performed linear measurements on subjects' faces (direct measurements) and both linear and angular measurements on all images (indirect measurements). For a qualitative analysis, 10 dental observers and an expert in facial imaging (subjective gold standard) completed a questionnaire regarding facial characteristics. The reliability of the quantitative data was evaluated using intraclass correlation coefficients, whereas the Fleiss kappa was calculated for qualitative data. Results: Linear and angular measurements carried out on 2D and 3D images showed excellent inter-observer and intra-observer reliability. The 2D photographs displayed the highest combined total error for linear measurements. SPG performed better than LS, with borderline significance (P = 0.052). The qualitative assessment showed no significant differences among the 2D and 3D imaging modalities. Conclusion: SPG was found to a reliable and accurate tool for the morphological evaluation of soft tissue in comparison to 2D imaging and laser scanning.

The Open Dentistry Journal, 2018

Objectives: To assess the effect of two of the most commonly used sterilization techniques on 3D ... more Objectives: To assess the effect of two of the most commonly used sterilization techniques on 3D printed clinical objects. Materials & Methods: The two sterilization methods used in our hospital and investigated in this paper are: Steam heat and Gas plasma. Three objects were printed and tested in this study: a tooth replica, an orthognathic final splint, a surgical cutting guide for the purpose of mandible reconstruction. For each of the 3 objects, 4 copies were made: one original STL object, one copy of the object pre-sterilization, one copy of post-steam heat sterilization, and one copy of post-gas plasma sterilization. Each printed object was scanned using a high resolution CBCT protocol and the compared (morphologically and volumetrically). Results: At the level of volumetric changes, no difference was found between pre and post-sterilization for both methods evaluated. As for the morphological changes, only differences were noticed with the orthognathic splint object indicatin...

Biochemia medica, Jan 15, 2018

Analytical quality is an essential requirement for best practice in any medical laboratory. Lack ... more Analytical quality is an essential requirement for best practice in any medical laboratory. Lack of a harmonized approach for sigma calculation is considered an obstacle in the objective comparability of analytical performance among laboratories adopting sigma metrics. It is urgently needed that all laboratory professionals interested in the analytical quality to work hard towards harmonization protocol for sigma calculation in order to properly select their analytical goals. This study aims at harmonization of Sigma metrics calculation in four accredited Egyptian laboratories. This observational cross sectional study compared the sigma levels for certain biochemical parameters in the four participating laboratories. Coefficient of variation (CV) and bias were determined for some biochemical analytes, data assayed by different automated analysers in the four different accredited laboratories. The sigma level for the four medical laboratories was calculated for each biomedical parame...

STOMATOLOGY EDU JOURNAL, 2016

Introduction: Facial asymmetry is a three-dimensional problem and is common in humans. Depending ... more Introduction: Facial asymmetry is a three-dimensional problem and is common in humans. Depending on the severity of the condition and the cause, several treatment modalities are proposed. In this study, we report on our workflow treating facial mandibular asymmetries without malocclusion. Methodology: CT scans were used for preoperative planning and postoperative evaluation. 3D planning using the mirroring technique was presented and afterwards a simulated extension was 3D printed and used during the surgery for accurate harvesting and placement of the bone graft. Results: The surgical actual outcome when compared to the simulation revealed good approximation with a mean of 0.29 (± 1.73) mm. Conclusion: The proposed method can be considered promising for the treatment of facial mandibular asymmetry without affecting the occlusion. However, a larger scale prospective study should be conducted to confirm these findings.

Journal of Oral and Maxillofacial Surgery, 2017

Squamous odontogenic tumor is a rare benign epithelial odontogenic tumor of the jaw. Most are sol... more Squamous odontogenic tumor is a rare benign epithelial odontogenic tumor of the jaw. Most are solitary lesions, although rare multifocal lesions have been described. Maxillary lesions have more aggressive behavior. Because of their benign character, these lesions are usually treated using a conservative surgical approach with curettage and surgical enucleation. Here we present a case of a 29-year-old woman with multifocal lesions who was initially treated with conservative surgical therapy. Early recurrence 6-months post-surgery prompted more aggressive resection. The case is discussed in the context of current evidence related to the epidemiology, etiology, diagnosis, and therapy of squamous odontogenic tumors.

Journal of cranio-maxillo-facial surgery : official publication of the European Association for Cranio-Maxillo-Facial Surgery, 2017

To quantify the postoperative condylar remodelling and its role in skeletal relapse after bimaxil... more To quantify the postoperative condylar remodelling and its role in skeletal relapse after bimaxillary surgery. 50 patients with mandibular hypoplasia who underwent bimaxillary surgery were analyzed. CBCT scans were acquired preoperatively, one week postoperatively and two years postoperatively. 3D cephalometric analysis was carried out for each CBCT scan, after which the condylar volume analysis was performed. The maxilla was advanced by a mean of 2.1 mm with a corresponding mean relapse of 0.3 mm. The maxilla was impacted in 23 and extruded in 27 patients. The mean mandibular advancement was 7.8 mm. Two years after surgery a mean mandibular skeletal relapse of 1.3 mm was observed. 78% of condyles exhibited a postoperative reduction in volume of 179 mm(3) (mean), equivalent to 12.5 volume%. Postoperative condylar volume loss was correlated with mandibular skeletal relapse (r = 0.42, p < 0.01), but not with maxilla relapse. Linear regression analysis identified age, gender, amount...

Lecture Notes in Computer Science, 2010

Abstract. Observer performance experiments for lesion detection are an ac-cepted means of assessi... more Abstract. Observer performance experiments for lesion detection are an ac-cepted means of assessing the imaging performance of radiological imaging sys-tems. Simulation methods for clusters of microcalcifications have been proposed for creating images with abnormal ...